In recent times it has become more and more popular to offer fresh food, salads, fruit vegetables, chicken, but also cooked and prepared food, or so called healthy food, from what often is called a salad bar, where the customer can pick and compose a meal from a number of different products kept in canteens or pans. However, since the food products may remain for some time in the canteens, which may be accessed by quite a large number of persons, the requirements as to an appropriate and hygienic storage capability are high. Furthermore the food products have to be kept under such conditions, and at such a temperature, that bacterial growth is prevented and the products can be kept fresh, appetizing and are not ruined or deteriorated in any way due to the storing.
To be able to maintain an accurate temperature, e.g. above 0° (to avoid that the products be frozen), but below 8° C., several different arrangements have been proposed.
Most known arrangements use cooling elements below the canteens, but it is difficult to obtain an even temperature distribution in the food stored in the canteens, i.e. throughout the canteens, independently of the location of the food and of the canteens. This problem further is aggravated due to covering arrangements used to cover and protect the canteens with content frequently being opened by customers accessing the food, each time during a shorter or a longer time period
Therefore some known arrangements use fan blowers for blowing cold air onto the products e.g. from above, or from below or sideways onto the canteens.
This is however disadvantageous for several reasons. First, it is not good from a hygienic point of view, bearing in mind that several individuals serve themselves from the canteens which means that air contaminated with bacteria etc. may be blown onto the food. Also other particles, e.g. dust may be blown onto the food. Second, due to the air flow, the food products may be dried out, and ruined, at least from an aesthetical point of view and the products will not look fresh, which may reduce the willingness of customers to buy and consume the products. Some articles may even loose taste and undergo unwanted changes.
These factors contribute in shortening the time period the products can be kept in the canteens, and they may have to be disposed of, even if they actually could have been stored for a longer time if stored under appropriate conditions.
Third, it is a waste of energy to have fan blowers active all the time. Moreover, the difficulties in maintaining an appropriate temperature throughout the entire contents in a canteen, may lead to production of microorganisms, which even may give rise to health hazards.
Since, as referred to above, in general a covering arrangement is used to protect the products in the canteens, the problems referred to above are even more accentuated, since the opening and closing of such covering arrangements will affect the temperature distribution. When such covers or lids are opened to provide a customer with access to the food products, air of a higher temperature will enter the canteens, which means that even more cooling is required. If fans are used, the products will then be even more exposed to cool air, and the drying effect will be further increased, which means that the time period that the products can be stored in the food bar will be even more shortened. In addition thereto, when the covering arrangements, or the lids, are opened, this will contribute to an even more uneven temperature distribution. Covering arrangements used in known food bars are fixedly hinged at the rear side of the canteens, or of the food bar, and when they are opened, pivoted or rotated, around a shaft at the rear, lower edge of the cover, warm air, at room temperature, will enter from the front side of the food bar, and from the short sides.
The more often the food bar is accessed, i.e. the more often the cover is opened, the larger the problems associated with keeping of an even temperature distribution will be, and the losses in cooling power will be considerable.
Another disadvantage is that covering arrangements, or lids, fixedly hinged at the rear side will, when opened, sweep out across the food bar tray slide. This is very uncomfortable for a customer, and may even have as an effect that food collected by a customer in a package or similar on the tray may be hit and fall down onto the floor or be spilt on the tray slide, when the customer, or another customer, opens or closes the cover.